Why doesn't my medical bill match my EOB?

Your provider's bill and your insurer's Explanation of Benefits (EOB) are produced by two different systems that don't always sync in real time. Common causes of a mismatch include balance billing, duplicate line items, charges submitted before your insurer finished processing the claim, or coding differences between what the provider billed and what the insurer allowed.

What is an EOB (Explanation of Benefits)?

An EOB is the statement your insurance company sends after processing a claim. It shows the amount billed, the amount your plan allows, what insurance paid, and what it calculates as your patient responsibility. It is not a bill — it's your insurer's record of the claim.

Free · No account · Runs in your browser

Does your medical bill actually match your EOB?

Enter what the provider billed and what your insurer's Explanation of Benefits says. EOBCheck reconciles the two, flags anything that doesn't add up, and drafts the letter to ask why.

Check my bill — free See how it works ↓

Nothing you enter leaves your device. This is an informational tool, not legal or financial advice.

Example reconciliationSample

Provider bill — amount you owe$0

EOB — patient responsibility$0

Unexplained variance

Same claim, two different numbers — EOBCheck shows why.

How it works

Three steps, about a minute

Enter your numbers

Type in what your bill says and what your EOB says. No upload, no login, no waiting on hold.

Get your reconciliation

EOBCheck compares both documents and flags anything unexplained, in plain English — not insurance jargon.

Send your dispute

Download a letter asking your provider to explain or correct the difference, personalized to your numbers.

Why this happens

Bills and EOBs disagree more often than you'd think

Balance billing

A provider bills you directly for an amount your insurer never assigned as your responsibility.

Timing mismatches

The bill goes out before the insurer finishes processing, so the numbers were never going to match.

Duplicate charges

The same service or supply appears more than once on the itemized statement.

Coding differences

What the provider billed and what the insurer allowed were coded differently for the same visit.

The tool

Check your bill

Have your provider bill and your EOB nearby. You only need the totals — line items are optional.

What the provider billed

Provider or facility name optional

Bill date optional

Total amount billed

Amount the bill says you owe Sometimes labeled "patient balance" or "amount due."

What your EOB says

Total amount billed (per insurer)

Allowed amount

Insurance paid

Patient responsibility (per EOB)

Good Faith Estimate optional

If you're uninsured or self-pay and received a written cost estimate before treatment, enter it here — we'll check it against the federal $400 dispute threshold.

Estimated total from your Good Faith Estimate

Your name (for the letter) optional

Your reconciliation report

Your dispute letter

Generated from your numbers. Edit anything before you send it.

Copied ✓

What to do next

Pricing

Start free. Pay only for the complicated ones.

Free

One bill, one EOB.

Total-level reconciliation
Red / amber / green flags
Plain-English explanation
One dispute letter

Check my bill

Full report

$9.99

One bill, fully itemized.

Everything in Free
Line-item reconciliation
Good Faith Estimate dispute check
Detailed, editable dispute letter

Get the full report

Complex bill

$29–49

Multiple EOBs or providers.

Everything in Full report
Multiple bills reconciled together
Combined variance summary
One letter per provider

Get started

FAQ

Common questions

Your provider's bill and your insurer's Explanation of Benefits are produced by two different systems that don't always sync in real time. Common causes include balance billing, duplicate line items, charges sent before the insurer finished processing the claim, or coding differences between what was billed and what was allowed.

An EOB, or Explanation of Benefits, is the statement your insurer sends after processing a claim. It shows the amount billed, the allowed amount, what insurance paid, and what it calculates as your patient responsibility. It is not a bill — it's your insurer's record of the claim.

A Good Faith Estimate is a cost estimate that uninsured and self-pay patients are generally entitled to receive before a scheduled service. If your final bill is substantially higher than that estimate, you may be eligible to challenge it through a federal dispute process. Eligibility depends on the size of the gap and other requirements, so verify your specific situation before relying on this.

No. EOBCheck runs entirely in your browser. The numbers you enter are used to calculate your reconciliation and letter on your own device and are never sent to a server.

No. EOBCheck is an informational tool that checks arithmetic and flags common patterns — it does not replace a licensed patient advocate, attorney, or accountant. For anything time-sensitive or high-stakes, confirm with a professional.

Paid tiers aren't available for purchase yet. Once checkout is live, refund requests within 14 days of purchase for an unused report are eligible for a full refund. See the full Refund Policy for details.